Antoranz Canales, PedroBarrio Uña, Juan AbelContreras González, José LuisFonseca González, Mª VictoriaLópez Moya, MarcosMiranda Pantoja, José Miguel2023-06-202023-06-202005[1] Fonseca, M.V., Acta Physica Polonica B, vol. 30, 2331 (1999). [2] Oña-Wilhelmi, E., et al., Astropart. Phys. 22, 95 (2004). [3] Srinivasan, R., et al., Proc. Towards a Major Atmospheric Čerenkov Detector V, Durban (1997) p.51. [4] De Naurois, M., et al., ApJ 566, 343 (2002). [5] Franzen, A., et al., Proc. 28th ICRC, Tsukuba (2003). [6] Ostankov, A., et al., NIM A, vol. 442, Issue 1-3, 117 (2000). [7] http://www.magic.iac.es/subsystems/centralpixel/. [8]http://content.honeywell.com/sensing/prodinfo/infrared/catalog/0331eng.pdf. [9]http://content.honeywell.com/sensing/prodinfo/fiberoptic/application/on7eng.pdf. [10] http://sine.ni.com/nips/cds/view/p/lang/en/nid/11916. [11] Lucarelli, F., et al., ”The timing system of the MAGIC telescope”, Proc. of the 19th ECRS, Florence (Italy), 2004 (in preparation) and http://www.magic.iac.es/subsystems/timing.html. [12] Manchester, R.N., et al., MNRAS 328, 17 (2001). [13] http://www.jb.man.ac.uk/ pulsar/crab.html.https://hdl.handle.net/20.500.14352/53332International Cosmic Ray Conference (29.2005.Pune, India). The authors wish to thank the financial support given by the CICYT (project FPA2003-9543-C02-01) to make this work and the IAC for providing excellent working conditions in La Palma. The MAGIC telescope is mainly supported by BMBF (Germany), CICYT (Spain), INFN and MURST (Italy).The MAGIC telescope has been designed for the observation of the Cerenkov light generated in Extensive Air Showers. However, its 17 m. diameter and optical design makes it suitable for optical observations as well. In this work, we report on the development of a system based on the use of a dedicated photo-multiplier (PMT) for optical observations installed at the center of the MAGIC camera (the central pixel). An electro-optical system has been developed in order to transmit through optical fiber the PMT output signal to the counting room, where it is digitized and stored for off-line analysis. First tests of this system using the Crab nebula as calibration source show its optical pulsation.engbook parthttp://arxiv.org/ftp/astro-ph/papers/0508/0508273.pdfopen access537539.1Astronomy & AstrophysicsInstruments & InstrumentationPhysicsParticles & Fields.ElectricidadElectrónica (Física)Física nuclear2202.03 Electricidad2207 Física Atómica y Nuclear